SnSe-based limited reprogrammable cell

Abstract

Methods and apparatus for providing a memory device that can be programmed a limited number of times. According to exemplary embodiments, a memory device and its method of formation provide a first electrode, a second electrode and a layer of a chalcogenide or germanium comprising material between the first electrode and the second electrode. The memory device further includes a tin-chalcogenide layer between the chalcogenide or germanium comprising material layer and the second electrode.

1. A memory device comprising:
 a first electrode; 
 a second electrode; 
 one of a chalcogenide material and semi-metal material between the first electrode and the second electrode; and 
 a tin-chalcogenide material between the chalcogenide material or semi-metal material and the second electrode. 
 
     
     
       2. The memory device of  claim 1 , wherein a ratio of the thickness of the tin-chalcogenide material to the thickness of the chalcogenide material or semi-metal material is less than about 4:3. 
     
     
       3. The memory device of  claim 2 , wherein the ratio of the thickness of the tin-chalcogenide material to the thickness of the chalcogenide material or semi-metal material is greater than about 1:3. 
     
     
       4. The memory device of  claim 1 , wherein the chalcogenide material or semi-metal material comprises either germanium telluride or germanium selenide. 
     
     
       5. The memory device of  claim 1 , wherein the tin-chalcogenide material comprises tin selenide. 
     
     
       6. The memory device of  claim 1 , further comprising a metal material between the tin-chalcogenide material and the second electrode. 
     
     
       7. The memory device of  claim 1 , wherein the metal material comprises silver. 
     
     
       8. The memory device of  claim 1 , wherein a thickness of the chalcogenide material or semi-metal material and a thickness of the tin-chalcogenide material are such that the memory device is programmable a limited number of times. 
     
     
       9. The memory device of  claim 1 , wherein a thickness of the chalcogenide material or semi-metal material and a thickness of the tin-chalcogenide material are such that once the memory device is programmed, it cannot be erased. 
     
     
       10. A memory device comprising:
 a first electrode; 
 a second electrode; 
 a germanium comprising material between the first electrode and the second electrode; and 
 a tin-chalcogenide material between the germanium comprising material and the second electrode. 
 
     
     
       11. The memory device of  claim 10 , further comprising a metal material between the tin-chalcogenide material and the second electrode. 
     
     
       12. The memory device of  claim 10 , wherein the germanium comprising material is not a chalcogenide. 
     
     
       13. A method of forming a memory device, the method comprising the acts of:
 providing a substrate; 
 forming a first electrode over the substrate; 
 forming a second electrode over the substrate; 
 forming one of a chalcogenide material and semi-metal material, wherein the chalcogenide material or semi-metal material is located between the first electrode and the second electrode; and 
 forming a tin-chalcogenide material, wherein the tin-chalcogenide material is located between the chalcogenide material or semi-metal material and the second electrode. 
 
     
     
       14. The method of  claim 13 , wherein the chalcogenide material or semi-metal material and the tin-chalcogenide material are formed such that a ratio of the thickness of the tin-chalcogenide material to the thickness of the chalcogenide material or semi-metal material is less than about 4:3. 
     
     
       15. The method of  claim 13 , wherein the acts of forming the chalcogenide material or semi-metal material and the tin-chalcogenide material comprise forming the chalcogenide material or semi-metal material and the tin-chalcogenide material having thicknesses such that the memory device is programmable a limited number of times. 
     
     
       16. The method of  claim 13 , further comprising forming a metal material between the tin-chalcogenide material and the second electrode. 
     
     
       17. The method of  claim 13 , wherein the act of forming one of a chalcogenide material and semi-metal material comprises forming a germanium comprising material. 
     
     
       18. The method of  claim 13 , wherein the act of forming one of a chalcogenide material and semi-metal material comprises forming one of germanium telluride or germanium selenide.